Let's review the commands you have learned concerning mathematical operations. Highlight the area next to the word Answer to reveal the answer. If there are certain topics you don't feel confident in yet, don't worry. Just go back to the appropriate page and review.

1. True or False: Subtraction is the same as adding a negative number.

Answer: True. 5 - 2 = 5 + -2

2. Which of the following expressions are equivalent?

abs(-5)

-30 / 6

int(-5.5)

51

30 / 5

Answer: Choices 1 and 4, which both equal 5.

3. True or False: The complex number i squared is equal to one.

Answer: False. i2 = -1

4. Evaluate the following expression. Remember the Order of Operations.

(1)

\begin{equation} 24 / 4 + 2 * (9 - √9) / 3 \end{equation}

Answer: The answer is 10. Remember PEMDAS

5. Which of the following commands will calculate the number of possible 3-digit number lock codes? The code can use the numbers 0 - 30 and order does matter.

3 nPr 30

30 nCr 3

3 nCr 31

31 nPr 3

Answer: Choice 4. Order matters, making the code a permutation. The length of the code, or r, is 3 digits, and the number of possible digits. or n, is 31, because we can use all numbers from 1 to 30 as well as 0.

6. True or False: The default base of log(n) is 10.

Answer: True. To get a different base, use the logBASE function or the formula: log(x)/log(b) = logb(x)

7. Which of the following trigonometric identities is correct?

cos(x) - sin(x) = tan(x)

tan(x) + cos(x) = sin(x)

sin(x) / cos(x) = tan(x)

sin(x) * tan(x) = cos(x)

Answer: Choice 3.

8. The max() command can be used as a space-saving substitute for which kind of logical operator?

Answer: The operator OR. The min() command can be used as a substitute for AND statements.